Copying and duplicating apparatus

ABSTRACT

An electrographic copying apparatus and process for producing copies of graphic originals utilizing the electropowder process. The apparatus comprises a pod assembly for storing a supply of a photosensitive web material and for supporting sections thereof during imaging and development. The web material during development supported on the outer peripheral surface of the pod assembly and the developing surface is conductive to permit the electric field to be developed at the developing station. The pod preferably has a flat planar surface upon which the web is placed during imaging and a curved surface where the web is placed as the pod is moved during development. The pod is adapted for supporting two imaged sections to afford the production of two copies on each revolution of the pod.

United States Patent Moxness et al.

[54] COPYING AND DUPLICATING APPARATUS [72] Inventors: James G. Moxness,St. Paul; Harold H. Nelson, West St. Paul; Edward A. OMara, MaplewoodVillage, all of Minn.

[73] Assignee: Minnesota Mining and Manufacturing Company, St. Paul,Minn.

[22] Filed: April 24, 1970 [21] Appl. No.: 31,732

Related U.S. Application Data [63] Continuation of Ser. No. 640,547, May23, 1967,

abandoned.

[52] U.S. Cl. ..355/3, 355/64, 355/72, 95/17 [51] Int. Cl. ..G03g 15/00[58] Field of Search ..355/3, 64, 72; 95/17 [56] References Cited UNITEDSTATES PATENTS 3,354,S04 ll /l 967 lones n .i95/l4 [451 Dec. 19, 1972439,121 l0/1890 Crane ..95/17 Primary Examiner--.lohn M. HoranAttorney-Kinney, Alexander, Sell, Steldt & Delahunt [57] ABSTRACT Anelectrographic copying apparatus and process for producing copies ofgraphic originals utilizing the electropowder process. The apparatuscomprises a pod assembly for storing a supply of a photosensitive webmaterial and for supporting sections thereof during imaging anddevelopment. The web material during development supported on the outerperipheral surface of the pod assembly and the developing surface isconductive to permit the electric field to be developed at thedeveloping station. The pod preferably has a flat planar surface uponwhich the web is placed during imaging and a curved surface where theweb is placed as the pod is moved during development. The pod is adaptedfor supporting two imaged sections to afford the production of twocopies on each revolution of the pod.

15 Claims, 37 Drawing Figures SHEET MM 14 PATENTED DEC 19 I972 SHEETOUUF 14 Avnwrazs PATENTED on: 19 I972 SHEET UEUF 14VIIIIIIIIIIIIIIIIIIIIIIIIIIII I I i fla r W% 4 Mm 00 K SLR 50A WW Jflz 5a m0 1 PATENTED DEC 19 m2 SHEET UBUF 14 QM "-0" my 9Q w www o o .HKMMNMWMm Rn o r 5 0 QM Y 0 MW,

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PATENTED 19 3.706.489 sum nau 14 ZzhMM ram m P'A'TENTED on: 19 1912SHEET lOUF 14 EJZA JAMES .Mox/vzas's #92010 .Na so/v COPYING ANDDUPLICATING APPARATUS This application is a continuation of applicationSer. No. 640,547 filed May 23, 1967, now abandoned.

This invention relates to a newand improved apparatus and to a processfor electrographically producing. a copy of graphic intelligence usingan appropriate electronically conductive pigmented powder and anappropriate photoconductive web.

More particularly, in one aspect this invention relates to anelectrophotographic, duplicating machine adapted to reproduce on plainpaper oneor more co pies of a graphic original from an image of suchgraphic original formed on a photoconductive web carried by a podassembly which has relative movement todeveloping and transfer stationsto produce the copy or copies.

In another aspect, this invention relates to electrophotographic methodsfor copying graphic originals and to an apparatus for making multiple,copies of a given graphic original from a single image, thereof formedon a photoconductive web.

l-leretofore, in prior art electrophotographic;copying machines andassociated methods, in order to make a copy it was necessary to formfirst an electrostatic,

latent image of the graphic original on a photoconductive surface,usually on the surface of a revolving drum,

by uniformly electrostatically chargingthesurface followed by exposureof the charged surfaceto thelight image to be copied. The electrostaticlatent surface image is developed by attracting anelectroscopicmaking-powder imagewise to the remaining charged areas ofthe photoconductive surface of the drum. The electroscopic powder imageon the drum was then transferred to a copy sheet and later fixed. Thedrum surface served as an intermediate and if more than one-copy is tobe made the latent image must be reformedeach time on the drum.

Before the drum surface could be reused for forming the nextelectrostatic latent image, an elaborate clean-.

form an image of a graphic original upon-the cylindri-.

cally curved photoconductive surface, a scanning type optical system isnecessary and the. drum must be revolving. In a given apparatus, such anoptical system has fixed parameters so that only predetermined types ofgraphic originals can be copied without'completely redesigning theoptical system.

By the present invention there are provided apparatus and associatedmethods which overcome the shortcomings of the prior art and whichprovide new and improved techniques for electrographically copyinggraphic originals. Thus,- the presentinvention is suitable forpracticing the electropowder process, which is described in French Pat.No. 1,456,993, issued Sept. 19, 1966. By the electropowder process,.apho-.

toresponsive sheet, for example, a photoconductive surface, is exposedto alight image without preliminary electrostatic chargingtoform adifferentially COIldUC-,-

tive pattern corresponding to the light image and is then contacted withan, electrically conductive,

developerpowder whilesimultaneously a suitable electric potential isapplied between a conductive support or-backing for such imaged sheetand, the powder applicator sothat theimaged sheet is differentiallycoated with thepowder correspondingto the conductive pattern thereon.The resulting powder coated photoresponsive sheet is then contacted witha receptor sheet while simultaneously being placed'in a suitableelectricfield. Theresult is that a powder image'of the graphic originalis transferred from; thephotorespon-.

sive sheet-to the, receptor sheet so thata copy of a graphic original isthereby formed; When-the apparatus and methodsof this invention are.practiced, using theelectropowder process, more than one copy of agraphic, original can be made froma-single imaging operation simply byrepeating-all thestepsexcept the image exposurestep.

The, present invention provides inone machine not only the capacity, tomake. singlecopies of graphic originalsbut also thecapacitytomake-multiple copies of such graphic originals at relatively highspeeds. The

machine, is simple to, operate, has minimum makereadytime, andhasnoclean-up operation following a singlelormultiple-copying run.

Furthermore, the present invention provides ameans for projecting animageof-a graphic original on a planar surfaceybuilt'intothe drumso'that conventional optical projectiontechniques can be employed.

Accordingly, it is theobject of this invention to'provide a new improvedcopyingand. duplicating apparatus.

Another'object is to providea copying apparatuswherein thephotoconductive material is disposed within apodassembly, which in theiIlustrated embodiment is-a-drum means, supporting ;a,web of thephotoresponsive; material and affording movement of the web relativento,a developing and ;,transfer-station. The web may be movedjabout theouter'surface of thedrum in a sequence to place unused, portions in acopying position andrewindused portions. In the embodiment illustratedherein the pod assembly is movable and carries with it thesupply andrewoundroll of the web during the copying operation.

Another-object is to provide automated apparatus and method'useful forpracticing,electrophotographic copying. of graphic originals and; whichis especially useful for practicing the electropowder reproductionprocess.

Another object is toprovide, apparatus and associated methods suitablefor making multiple copies of a graphic original in good quality and athigh'speeds.

Another object is to provide apparatus and methods whereby one can, oncea photoconductive surface has been imaged by a graphic original usinglight exposure, prepare multiple copies of such graphic original fromsuch imaged photoconductive surface in a predetermined sequence ofoperations without re-exposing such photoconductive surface.

l060ll 0065 Other and further objects of the present invention willbecome apparent to those skilled in the art from the followingspecification taken together with the attached drawing wherein:

FIG. 1 is a representation of the device of the present inventionshowing the spatial positions of the various subassemblies relative toone another;

FIG. 2 is an enlarged end elevational view of the pod assembly showingspindle drive means and web path;

FIG. 3 is aside elevational view taken from the line 3-3 of FIG. 2;

FIG. 4 is a vertical sectional view taken along the line 4-4 of FIG. 3;

. FIG. 5 is an enlarged detailed sectional view taken along the line 5-5of FIG. 3; I

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 4;

FIG. 7 is an enlarged detailed sectional view taken along the line 7-7of FIG. 3;

FIG. 8'is an enlarged detailed partially sectional and perspective viewtaken along the line 8-8 of FIG. 4;

FIG. 9 is an enlarged detailed sectional perspective view taken alongthe line 9-9 of FIG. 4;

FIG. 10 is an enlarged detailed sectional view taken along the line10-10 of FIG. 3;

FIG. 11 is an enlarged detailed sectional view .taken along the line11-11 of FIG. 3;

FIG. 12 is an enlarged detailed sectional view taken along the line12-12 of FIG. 3;

FIG. 13is an enlarged detail view taken through the region 13-13 of FIG.3 and also as indicated in FIG. 14;

FIG. 14 is a vertical sectional view taken along'the line 14-14 of FIG.13;

FIG. 15 is a horizontal sectional view taken along the line 15-15 ofFIG.13;

FIG. 16 is an enlarged detailed sectional view taken along the line16-16 of FIG. 2;

FIG. 17 is an enlarged detailed sectional view taken through the region17-17 of FIG. 3;

FIG. 18 is a side elevational view of the web advance mechanism shown inFIG. 17;

FIG. 19 is a vertical sectional view of the web advance mechanism;

FIG. 20 is an enlarged fragmentary detail view of the web brake;

FIG. 21 is an enlarged fragmentary detail view showing a web meteringmeans and grounding roll;

FIG. 22 is a detail view of the web metering means illustrated in FIG.22;

FIG. 23 is a diagrammatic representation showing one interrelationshipbetween a first microswitch and a first cam used in the web meteringmeans shown in FIGS. 21 and 22;

FIG. 24 is a view similar to FIG. 23 but showing another relationshipbetween a second microswitch and a second cam used in the web meteringmeans shown in FIGS. 21 and 22;

FIG. 25 is a fragmentary detail view of the grounding roll and drum; v

FIG. 26 is a partially sectionalized and elevational view of a drumbrake;

I FIG. 27' is an elevational and partially sectional view of thedeveloping assembly;

FIG. 28 is a fragmentary plan view of the rollers in the developingassembly;

FIG. 29 is an enlarged vertical sectional view of the magnetic roller ofthe developing assembly taken along the line 29-29 of FIG. 28;

FIG. 30 is a vertical sectional view of the light-exposing means;

FIG. 31 is a plan view of the transfer assembly; a

FIG. 32 is a sectional view taken approximately along the line 32-32 ofFIG. '31;

FIG. 33 is a vertical sectional'view of the transfer roll; a

FIG. 34 is an elevational view of the transfer assembly shown in FIGS.31 and 32;

FIG. 35 is a view illustrating an operation of the copy sheet clampingmechanism employed in the transfer assembly of FIGS. 31-34;

FIG. 36 is a view similar to FIG. 35 but illustrating mechanism in adifferent location as the transfer roll revolves clockwise; and a FIG.'37 is a block diagram of an electrical control and programming circuitfor the device of the present invention.

The operational principles of this invention will be understood byreference to FIG. 1 where there is shown a schematic side-elevationalview of an apparatus constructed in accordance with the presentinvention. This embodiment of the apparatus is designated in itsentirety by the numeral 101 and comprises several cooperatingsubassemblies designated in their respective entireties as a podassembly or drum means 102, a

web imaging or image projecting means 103, an image developing means104, sheet feeding means 105, image transfer means 106, and fusing means107. In a duplicating apparatus or one; designed to make multiple copiesa source of columnated light or light-exposing means 108 and a groundingmeans 109 are provided as will be hereinafter explained. Thesesubassemblies are independently supported and positioned within acabinet or frame 135.

The pod assembly or drum means 102 includes a generallycylindrically-shaped casing'or drum which has mounted therein a supplyroll ,110 of a photoconductive web 111, and a take-up roll 112 for thesame. The outer peripheral surface of the drum is formed by an imagingplate 114 which has a substantially flat exterior surface positionedwithin the (projected) circumferential periphery of the drum and atleast one electrically isolated, electrically conductive semicylindricalpad means 115. Pad means 115 is preferably adjacent the imaging plate114. Means (illustrated hereinafter) is provided to advance and positiona portion of web 111 from roll 110 first upon plate 114 and then on thepad means 115, and means (illustrated hereinafter) is provided forrotating the drum means 102 about its axis.

The image-projecting means 103 is illustrated herein as an opticalprojecting system for directing a light image of a graphic original 130onto the section of web 11 1 positioned over imaging 'plate 114.

Image developing means 104 is a system (discussed hereinafter) forapplying a fusable magnetically responsive pigmented powder 120 onto theimagebearing portion of web 111 in the presence of a simultaneouslyapplied electrical field, after said imaged portion is indexed fromplate 114 to a position over pad means 115, and the drum is advanced tocarry pad means 115 past said developing means. The powder 120 is atleastsemiconductive in the electrical field applied at the developingmeans. In the illustrated device pad means 115 comprises a pair ofsimilar circumferentially spaced pad assemblies 169 and 170 each havingelectrically conductive surfaces.

Sheet feeding means 105 may be any suitable receptor feeding mechanismfor feeding a copy sheet 126 from a supply thereof into theimage-transfer means 106.

Image-transfer means 106 is a system (illustrated hereinafter) affordingthe transfer of a developed powder image from web 111 to a receptor orcopy sheet 126.

Fusing means 107 receives copy sheet 126 from image-transfer means 106and fuses the powder 120, transferred or deposited in an imagewisepattern onto sheet 126 as by heating.

The light-exposing means 108 includes a source of light mounted within ahousing formed to permit exposure of the developed web to light,essentially all rays emitted being parallel and directed to impinge onthe pad means 115 across at least the full width of the web 111. At thislight-exposing means or station 108 the previously light exposed areasof the web 111 which have no developer powder retained thereon arere-exposed making such areas of optimum conductivity when web 111 isphotosensitive.

The grounding means 109 includes a roller engageable with the web 111 asit is carried past the transfer means 106, which roller serves to bleedoff any charges which have built up on web 111 or on the conductivesurface of pad means 115. In making multiple copies this grounding means109 reduces the state of charge so that the web will be presented to thedeveloping means 104 at the same electrical condition on each cycle.

For use with a photoconductive material as the intermediate web theoperation of apparatus 101 is as follows. A predetermined section orlength of photoconductive web 111 is placed on imaging plate 114 as aresult of it being advanced (e.g. translated or indexed) from supplyroll 110 through a slot in the cylindrical drum surface onto saidimaging plate 114. A light image of a graphic original 130 is projectedby image projecting means 103 onto the web at the imaging plate 114,thereby producing on the so-exposed section of web 111 a differentiallyconductive pattern corresponding to the projected image. The resultingexposed section of web 111 is then moved from imaging plate 114 onto padmeans 115 of the drum means 102 by advancing web material from thesupply roll and rewinding a portion of the web on the take-up roll.Next, the drum means 102 is rotated (counterclockwise as viewed in thedrawing) so that the image section of web 111 and pad means 115 aremoved together past the development means 104 where the powder 120 isapplied in a series electrical circuit arrangement with an appropriateelectrical potential'to the non-light struck or image-forming areas onthe section of web 111 disposed on the pad means. The powder will adhereto the web 111 corresponding to the pattern of the visible graphicoriginal 130. Continued rotation of the drum carries the developed imagepast the exposing means 108 which re-exposes the areas of the imagehaving no developer powder thereon.

As the resulting powder-developed pattern on web 111 advances uponrotation of the entire drum means 102 to the image-transfer means 106, acopy sheet 126 is fed from sheet-feeding means 105 into imagetransfermeans 106 to be aligned, registered, and placed in face-to-face contactwith the image section of the web. During continued rotation and whilethe web section is progressively placed in contact with the copy sheetthe powder developed image on web 11 1 is transferred, in the presenceof a second electrical potential to the surface of copy sheet 126 in animagewise pattern corresponding to that of the graphic original 130. Asthe copy sheet leaves the image-transfer means 106 it is picked up bythe fusing means 107 where the powder is fused to the copy sheet 126,thereby completing the production of a first copy from the graphicoriginal 130. The drum, upon continuing its rotation passes groundingmeans 109 to short out" or remove any charges built up on the surface ofweb 11 1.

If more than a single copy is desired, drum means 102 continues torotate without being reimaged at the image-projecting means 103, so thatthe image area of web 111 again passes, sequentially the developmentmeans 104, exposing means 108 and moves to transfer means 106, whereuponan additional copy sheet is fed in timed relationship from sheet feedingmeans 105 to transfer means 106 and through the fusing means 107. Theoperation is repeated until the desired number of copies have been made.At the completion of a duplicating operation, the drum means 102 returnsto a home or base position (e.g. a position such as illustrated inFIG. 1) where another copying operation can be undertaken as desired.

This embodiment will now be described in detail.

Image Projecting Means The imaging means 103 comprises a transparentsupporting stage 131 upon which the original may be placed, illuminatingmeans for the stage and original in the form of suitable lamp andreflector assemblies 132, a pair of first surface reflectors. 133 and134 and projection lens means 136 positioned between said reflectors.The reflectors 133 and 134 and the lens means 136 project and direct alight image of the original to a particular area on the surface of drummeans 102, which area is on the imaging plate 114. A shutter is disposedrelative to the projection lens means 136 to control exposure. Theshutter is controlled from a timer to afford the proper exposure and theimaging system projects an image of the entire original onto the webwhen the shutter is open.

Drum Means: Frame and Drive FIGS. 2 through 16 show one embodiment of adrum means 102. In this embodiment the drum means is defined by thecombination of a pair of circular, spaced, parallel, axially aligned endwalls 141 and 142 (see FIG. 3), which are maintained in fixed spatialrelationship to one another by threespanner members 146, 147 and 148(see FIG. 4), each of which is duly secured to an adjoining end wall 141and 142 by appropriate means, such as screws 149 or the like. Each endwall 141 and 142 and each spanner member 146, 147 and 148 is formed of anonconductive plastic, such as phenolic resin, or the like. Observe thatthe exterior surface portions of spanner members 146,147 and 148 areeach formed so as to have curvatures corresponding to the radius ofcurvature of the spaced end walls 141 and 142.

Affixed'one on each end wall 141 and 142 so as to lie on the axis 139 ofthe drum are a pair of aligned, outwardly oppositely extending stubshafts 153 and 154,

'respectively (see FIG. 4). Stub shafts 153 and 154 are a stub shaft 154and the entire drum means 102 is driven by means of an electric motor156, through the image transfer means 106 by an interconnecting timingbelt 157, in timed relation with said image transfer means.

Mounted in and between end walls 141 and 142, and circumferentiallyspaced from one another are two similar guide roller assemblies 161 and162 and a third guide roller assembly 165. Each of the assemblies 161and 162 is located such that its respective roller surface I portion isparallel to the axis of the side walls and substantially flush with theadjacent peripheral edges of end walls 141 and 142. Construction detailsof the guide roller assemblies 161 and 162 are described I below.

Circumferentially spaced from guide roller assemblies 161 and 162 iscapstan assembly 163 which is mounted between end walls 141 and 142.Capstan assembly 163 is located both so as to have its axis parallel tothe axis of the drum means, and so as to have its circumferentialsurface portions generally aligned with the adjacent peripheries ofrespective end walls 141 and 142. constructional details of capstanassembly 163 are described below. I

Positioned within theinterior of drum means 102 and mounted between endwalls 141 and 142 are a pair of spindle assemblies, one being designatedas supply.

spindle assembly 144, and the other being designated as takeup spindleassembly 145. These spindle assemblies 144 and 145 are each positionedso as to have their respective axes parallel to the axis of the drummeans 102. The spindle assemblies 144 and 145 are so spaced from oneanother that a supply roll 110 of the web 111 can be mounted on spindleassembly144 and be transferred to spindle assembly 145 withoutinterferring with the operation of each other. Constructional details ofeach spindle assembly 144 and 145 are described below.

Referring to FIG. 6, there is seen a vertical cross sectional view ofguide roller assembly 161. Assembly 161 is shown to have a dead shaft188, which is mounted between end walls 141 and 142, respectively, by apair of shoulder bolts 189. Centrally journaled on dead shaft 188 bymeans of a pair of bearing members 191 is roller 192 conveniently formedof steel or the like. Adjacent each opposite end of roller 192, andspaced therefrom by a thrust washer, is journaled one end of a pair ofangle members 196 and 197 respectively (which together provide a pivotalor hinge support for the imaging platform or plate 114 as belowdescribed). Retainer clips maintain the roller 192 centered on deadshaft 188. Guide roller assembly 162- in this embodiment is similar toguide roller assembly 161 except, of course, the angle members 196 and197 are absent.

The web guide roller assembly 165 (see FIG. 16) comprises a dead shaft198, mounted between axially spaced projections 180 by bolts 199, theheads of which are accommodated in grooves formed in the end walls 141and 142, and a roller 200 journaled on the shaft 198 by suitablebearings as best shown in FIG. 20. The roller 200.is formed of steel andcovered with a layer of resilient material having a high frictioncoefficient like natural rubber.

Drum Means: Imaging Platform In drum means 102 (see FIGS. 3, 4, and 6),located between guide roller assembly 161 and capstan assembly 163, andbetween and entirely within the periphery of both end walls 141 and 142,is the planar imaging plate 1 14 which has a planar base member 201 witha pair of rigiditizing channels having upright portions 202 and 203disposed along opposite sides thereof. Upright portions 202 and 203 areformed so as to fit within the periphery of the end walls 141 and 142 inthe assembled drum means 102. On one end of base member 201, and securedto one .end of each upright portion 202 and 203, is a hinge formed bythe angle members 196 and 197, (FIGS. 3 and 4) which are,

themselves journaled at one end for pivotal swinging DRUM MEANS: PADASSEMBLIES Between guide roller assemblies 161 and 162, and also betweenguide roller assembly 162 and capstan assembly 163 are the padassemblies169 and 170,

v respectively. The pad assemblies 169 and 170 form circumferentiallyspaced portions of a circumferentially extending surface of the drumbetween end walls 141 and 142. Each pad assembly'169 and 170 comprises acircumferentially extending member 210 (see FIGS. 4, 8 and 9) formed ofan electrically conductive material, and has a raised central surfacearea which supports the web material 1 11. A layer 211 of a low frictionelectrically conductive material is suitably'secured to and covers theraised area of the conductive member 210 to allow easy movement andsmooth operation of the photoconductiveweb 111 over its surface. Whenweb 111 has an electrically conductive backing to serve as the fieldelectrode, layer 21 1 may be thin paper.

In the case of pad assembly 169, an angle or rib member 175, of metal orthe like, is fastened along its opposite side edges to member 210 tosecure the member to the end walls 141 and 142 (FIG. 8) by convenientfasteners such as bolt and nut assemblies 214 and cap screws 216,respectively. Axially extending end members 217 and 218 join the ribs175 at the ends of the pads (FIG. 4). The pad assemblies 169 and 170 aresubstantially similar except that the assembly 17 0 is hinged to theside walls and therefore the ribs extend beyond member 210 at each endto forma hinge or pivot at one end, in conjunction with opposed pins 179as illustrated in FIG. 4, and to support the guide roller assembly 165at the opposite end. A pair of opposed pins 181 (FIG. 4) extend towardsone another through the end walls 141 and 142 and the ribs 175 of pad170 to secure the pivotal pad assembly 170 in operating position. Thesepins 181 may be similar to pins 208 and 209 and may easily be withdrawnfrom the ribs 175 affording pivotal movement of the entire pad assembly170 and the guide roller assembly 165, thereby providing access to theinterior of drum means 102. Circumferentially extending slots are formedat each end of spanner member 146 so that swinging movements of the padassembly 170 are not impeded.

Electrical contact can conveniently be made with the members 210 of padassemblies 169 and 170 by means of a wire lead (not shown) secured to ascrew. Electrical contact is made with the drum by conventional slirings (not shown). I

Drum Means: Supply and Take-Up Spindles Referring to FIG. 10, there isseen a vertical crosssectional view of supply spindle assembly 144.Assembly 144 employs a driven shaft 226, one end 227 of which has ashoulder formed thereon for axially supporting a center bored circularend cap or core supporting collar 228. A nut 229 isthreadably receivedon shaft 226 adjacent end 227 to releasably retain the collar 228 on theshaft 226.'Shaft 226 is reduced adjacent its other end 231 to providetwo shoulders 233 and 234 to snugly fit in the bore of a collar 235which is pressed against shoulder 233 and to be received in a suitablebearing 236. Bearing 236 is mounted within a threadably mounted bearingsupport 237 which'support is mounted in a threaded cap 238 fixed on endwall 141. The support 237 is manually adjustable by an exterior flange239 having circumferential knurled edge portions. In aligned opposedrelationship with the axis of bearing support 237 and mounted through anaperture in end wall 142 is a second bearing support 241. The bearingsupport 241 supports a pair of aligned bearings journaling one end of astub shaft 243, the other end of which is shouldered and formed with akeyway to fixedly support a pulley 245 thereon. The pulley 245 is formedwith an axially extending tapered hub portion which mates an interiorchamfer formed on the collar 228 as shown. The resulting relationshipbetween stub shaft 243 and driven shaft 226 is such that, when theentire spindle assembly 144 is duly mounted between end walls 141 and142, shafts 243 and 226 are coaxial with one another and pulley 245frictionally drives collar 228 and a supply roll core 247.

The core 247 is conventionally formed of cardboard and has an axiallyextending slot formed in one end to ensure driving engagement with thecollar, such as 228 which may have an axial rib engageable with saidslot. To remove a core 247 and a roll 110 of the web 111 from theassembly 144, bearing support 237 is threadably moved in cap 238outwardly until the bearing 236 and shaft 226 are axially separable.Then collar 228 can be separated from pulley 245 and shaft 226, core 247and collars 228 and 235 are removed from the drum means 102. When theyare removed, the nut 229 can be removed and collar 228 slipped off theshaft 226. The core and web may then he slipped off the 3077 O Ois E Momshaft. To mount a fresh supplyroll of web material 111 on the assembly144 a reverse procedure is followed but care is used to align theslotted core with the rib on the collar 228.

As will be appreciated from the subsequent description herein, inaccordance with the teachings of this invention, a supply roll 110 (notshown in FIG. 10) comprises a wound web of photoconductive material 111on a core 247. Thus, when pulley 245 is rotated, core 247 rotatesadvancing photoconductive web 111 therefrom or rewinding photoconductiveweb thereon, depending upon the direction of rotation.

Referring to FIG. 11, there is seen a vertical crosssectional view oftake-up spindle assembly 145. Assembly 145 has a shaft 251 supporting atake-up drum 252 having axially spaced end caps 253 and 254 press fittedon the shaft 251. A pulley 255 is keyed to shaft 251 adjacent the cap254 to drive the drum 252. The opposite ends of the shaft 251 extendbeyond the ends of the drum 252 and pulley 255 and are suitablysupported by bearings and bearing supports in the end walls 141 and 142.This take-up spindle assembly 145 winds the web-111 after it has beenadvanced around the outer peripheral surface portion of drum means 102.

Drum Means: Web Drive A capstan and guide roller combination providemeans for advancing the web 111 from the supply roll assembly to theouter surface of the drum means 102.

Referring now to FIG. 12 there is seen a vertical cross-sectional viewof capstan assembly 163. Assembly 163 comprises a roller 261 formed by arigid core 262 which has a uniform coating 263 of resilient material,such as a neoprene synthetic rubber, or the like. Mounted within eachend of core 262 is an end cap 264, which caps are fixed on a shaft 265.A pair of bearing supports 266 and 267 are mounted in aligned axialrelationship to one another through end walls 141 and 142, respectively,and each bearing support is suitably fixed to its respective end wall.The shaft 265 extends through bearing support 267 and the extendedportion has a pulley 268 axially mounted thereon by suitable means, forexample, a wedge tightener 269 and a key (not shown). The pulley 268thus affords a drive means for the capstan or roller 261.

Guide roller means are provided adjacent the surface of the roller 261to maintain web 1 1 1 in driving engagement with a substantial portionof the driven roller 261. In the present embodiment the guide rollermeans is a roller 270 (see FIGS. 3, 4, 13, 14 and 15), which isrotatably mounted on a dead shaft 272. The dead shaft 272 supported byindependently adjustable brackets 273 is mounted on the end walls 141and 142. The roller 270 has a rigid core coated on the outercircumferential surface with a resilient elastomeric material, such asnatural or synthetic rubber, giving the roller a dense high coefficientof friction surface.

The brackets 273 each comprise a base plate 276 secured to theassociated drum end wall by means of screws 277. One end of each baseplate 276 is located so as to be adjacent the roller 261 of the capstanassembly 163, each such end being characterized by an inturned ear 278(see FIGS. 13 and 14). The base plate 276 is also formed with opposedflanges 279 and 281

1. An electrographic copying machine adapted to produce a copy ofgraphic intelligence on a photoconductive web material, said copyingmachine comprising a. a pod assembly including internal means forstoring a supply of web material, an external peripheral imaging sectionand an external peripheral electrically conductive developing sectionspaced from said imaging section, and means for moving said web materialfrom said storing means over said imaging section and from said imagingsection to said electrically conductive developing section of saidassembly. b. imaging means for registering graphic intelligence on asaid web material when disposed on said imaging section, c. developingmeans including a conductive distributor means for applying conductivepowder to the web material on said developinG section, and meansconnected to said distributor means and to said developing section forapplying an electric field between said conductive distributor means andsaid developing section to carry said powder to said web, and d. meansfor moving said pod assembly to move said external electricallyconductive developing section containing said web material thereon froman initial position past said developing means whereby a visible patternof such graphic intelligence is produced on said web material and toreturn said developing section to said initial position.
 2. Anelectrographic copying machine adapted to produce a copy of graphicintelligence on a radiation responsive web material utilizing theelectropowder process, said copying machine comprising a. a generallycylindrical pod assembly mounted for rotative movement about its axis,including
 2. support means defining an external surface over which asaid web material is moved from said internal means, said externalsurface including an imaging section and a developing section, 2.distributor means for carrying pigmented conductive material to a saidsection of web material on said developing section in conductive contactwith said web, and
 2. a second electrical field producing means forsubsequently establishing an electrical field between said means forbringing a receptor into contact with said web material and saidsemi-cylindrical surface for transferring the conductive material fromsaid web material to said receptor.
 2. electrical field producing meansfor concurrently establishing an electrical field between said rollerand said semi-cylindrical surface of said pod assembly to depositconductive material onto said web material, and e. means for rotatingsaid pod assembly from said reference position to said developing meansfor developing said image pattern imparted to said photoconductive webmaterial.
 2. means extending parallel to the axis of said pod assemblyrotatably supporting said supply roll,
 3. means defining an externalperipheral surface for said pod assembly including a planar surface anda semi-cylindrical surface defining a path of movement for said webmaterial about said pod assembly, and
 3. conductor means connected tosaid distributor means for establishing an electric field between saiddistributor means and a said web section to form a visible pattern ofsuch graphic intelligence on said section of web material by depositingsome of said conductive material on insulative areas of said webmaterial as the same is advanced on said developing section of said podassembly to said developing means, d. driving means for said drivenmeans to move said web material about said imaging and developingsections of said pod assembly, and e. means for rotating said podassembly to move said developing section from an initial position tosaid developing means to produce a visible pattern of the graphicintelligence on a said section of web material and returning saiddeveloping section to said initial position.
 3. An electrographiccopying machine according to claim 2 wherein a transfer station isdisposed adjacent the periphery of said pod assembly, said transferstation comprising means for bringing a receptor into intimate contactwith a said section of said web material disposed on said developingsection, and means for imparting an electrical field between saiddeveloping section and said transfer station when a said receptor isplaced in contact with said web material to transfer the image formed bysaid conductive material to said receptor.
 3. internal restoring meansfor said web material after movement thereof over said support means,and
 4. driven means for moving the web to position successive sectionsof said web on said imaging section and for advancing said sections ofsaid web onto said developing section of said pod assembly, b. imagingmeans for projecting an image bearing graphic intelligence onto a saidsection of web material when disposed on the imaging section of said podassembly, c. developing means including
 4. An electrographic copyingmachine according to claim 2 wherein said imaging section of saidsupport means is a planar surface.
 4. means supporting said pod assemblyfor rotation about the axis of said semi-cylindrical surface, b. meansfor advancing a predetermined length of said web from said supply rolland advancing the web over said peripheral surface of said pod assembly,c. imaging means for projecting an image bearing graphic intelligenceonto said web material when said pod assembly is at rest with sAidplanar surface disposed at a reference position, d. developing meansincluding
 5. An electrographic copying machine according to claim 2wherein said external surface of said support means includes a planarimaging surface and two circumferentially spaced semi-cylindricaldeveloping surfaces defining said developing section, each saidsemi-cylindrical surface having an area to receive an imaged section ofweb material and each said semi-cylindrical surface being conductive andelectrically isolated.
 6. An electrographic copying machine according toclaim 2 wherein said internal means comprises a rotatable spindleasseMbly, said internal restoring means comprises a driven take-upspindle assembly, and said driven means comprises a driven capstan fordrawing a said web material from a roll supported on said rotatablespindle assembly and drive means for said internal restoring means, saidcapstan being disposed in adjacent relation to said imaging section ofsaid support means, said spindle assemblies and said capstan beingdisposed parallel to the axis of said pod assembly and being mounted attheir ends in end walls of said pod assembly.
 7. An electrographiccopying machine according to claim 6 wherein said means for driving saiddriven means comprises a drive system supported adjacent an end wall ofsaid pod assembly, said drive system comprising drive shafts supportedby said pod assembly and connected to said capstan and driven take-upspindle assembly, coupling means affording releasable driving engagementwith said drive shafts when said pod assembly is in its initialposition, motor means for driving said coupling means, and means formoving said coupling means into and out of driving engagement with saiddrive shafts as desired to advance a said web material.
 8. Anelectrographic duplicating machine adapted to reproduce one or morecopies of a graphic original from a photoresponsive web onto a receptor,said duplicating machine comprising a. a pod assembly including a planarimaging surface and a part cylindrical surface, internal means forstoring said photoresponsive web, means mounting said assembly forrotation about an axis coaxial with said cylindrical surface, and meansfor indexing a section of said web from said internal means over saidimaging surface and said cylindrical surface of said pod assembly, b.imaging means for projecting a light image of a said graphic original ona said web overlying said imaging surface to form a differentiallyconductive image pattern on said web when said pod assembly is in aninitial position, c. developing means including conductive roller meansfor applying a pigmented conductive developer powder against said web inconductive contact with said roller means and said web during movementof the cylindrical surface past said developing means, d. means forconcurrently applying an electrical field in the region between saidroller means and said cylindrical surface to develop a visible image ofsuch graphic original on said web, e. transfer means including anelectrically conductive member affording intimate contact between theresulting imaged web and a said receptor, f. means for establishing asecond electrical field between said cylindrical surface and saidconductive member for transferring said developer powder forming saidvisible image on said web to a said receptor when in said intimatecontact, and g. means for producing relative sequential movement of saidpod assembly from said initial position past said developing means andsaid transfer means whereby an image of such graphic original isreproduced on a said receptor.
 9. An electrographic copying machineadapted to produce a copy of a graphic original on a receptor, saidcopying machine comprising a. a pod assembly comprising
 10. Anelectrographic copying machine according to claim 9 wherein f. transfermeans are provided including
 11. An electrographic copying machineaccording to claim 10 wherein said semi-cylindrical surface iselectrically conductive to define a field electrode for said developingmeans and said transfer means.
 12. An electrographic copying machineaccording to claim 10 wherein said web material has a conductive backingforming a field electrode cooperating with said applicating roller andmeans for bringing a receptor into contact with said web material toform said electrical fields.
 13. An electrographic copying machineaccording to claim 10 including fusing means for fusing said conductivematerial to said receptor, and means for directing said receptor to saidfusing means from said transfer means.
 14. An electrographic copyingmachine according to claim 5 including control means for operating saidimaging means, said driving means and said means for rotating said podassembly to afford exposure of a section of a said web material on saidimaging section, advance said section to one said semi-cylindricaldeveloping surface, exposing the subsequent section of web material onsaid imaging section, advancing said web material to move the firstsection to the other semi-cylindrical developing surface and saidsubsequent section to said one semi-cylindrical developing surface, andthen rotate said pod assembly to move said developing surfaces and websections past said developing means and said transfer station to producethe desired copies of said graphic intelligence.
 15. An electrographicduplicating machine adapted to produce a plurality of copies of agraphic original, said copying machine comprising a generallycylindrical rotatable pod assembly, said assembly comprising means forsupporting a supply of web material comprising a coating ofphotoconductive material on a nonconductive support layer, rotatablemeans for rewinding used portions of said web material, said meanssupporting said supply and said rewinding means being positioned withinthe peripheral extent of said assembly, the periphery of said assemblybeing defined by a planar member disposed within the periphery ofaxially spaced circular end walls and by a pair of spacedsemi-cylindrical electrically conductive pads about which said webmaterial may be moved from a supply and said rewinding means, means formaintaining said assembly in a fixed position, imaging means forprojecting an image onto said planar portion of the periphery of saidassembly while said assembly is in said fixed position, means foradvancing said web material to move the exposed section of said materialdisposed on said planar member to a position in register with oNe ofsaid arcuate pads, control means for again exposing a new section ofsaid web material disposed on said planar member and for again advancingsaid second exposed section to registry with one of said pads, means forrotating said assembly, means adjacent the rotational path of said padsfor first depositing a pigmented powder material on said web materialand then transferring said powder to a copy sheet, said means fordepositing and transferring said powder material including means forestablishing an electrical field during said depositing andtransferring, and means for feeding copy sheets into register with theimaged sections of said web material disposed on said pads.